1. Field of the Invention
The present invention relates generally to connection-oriented networks such as ATM (asynchronous transfer mode) networks, and more specifically to a source routing method for fast re-establishment of connections when source user's demand is not supported when a connection is being established or already established.
2. Description of the Related Art
In a connection-oriented network where the source routing scheme is employed, connection setup is performed on a distributed management basis by having network nodes autonomously exchange topological state data so that they maintain an identical topology data base. Private Network-Network Interface Specification Version 1.0 (PNNI 1.0), ATM Forum, Technical Committee, March 1996, page 17, describes a "flooding procedure" in which topology state packets are flooded through a network to update topology database of each network node. The flooding topology state message is transmitted from one node to all neighbor nodes on a hop-by-hop basis with the neighbor nodes returning acknowledgment messages. As a result, the flooding message takes time to reach distant nodes away from the point of origin. Therefore, in a connection-oriented network where source routing is employed, it takes time for a source node to reestablish a connection in the event of a network failure if the flooding message is used solely as a fault recovery mechanism.